Patents by Inventor Vicente B. Lasmarias

Vicente B. Lasmarias has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Method for preparing acid resistant calcium carbonate pigments
    Patent number: 5164006
    Abstract: A method for preparing an acid resistant calcium carbonate pigment. An aqueous slurry of particulate calcium carbonate is provided at a pH of from about 11.0 to 12.0 and having from 2 to 5 g/l of excess calcium hydroxide. The slurry temperature is brought to the range of about 75.degree. to 80.degree. C., and sodium silicate solution is slowly mixed therewith to provide on a solid dry weight ratio from about 5 to 10% sodium silicate to calcium carbonate. Gaseous carbon dioxide is added to bring the slurry pH to the range of about 10.2 to 10.7, and the slurry is cooled to about 25.degree. to 30.degree. C. Finally zinc chloride is added to the cooled slurry to bring the pH to within the range of 7.5 to 8.0.
    Type: Grant
    Filed: April 8, 1991
    Date of Patent: November 17, 1992
    Assignee: ECC America Inc.
    Inventors: Vasant D. Chapnerkar, Vicente B. Lasmarias, Vijay K. Mathur